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Tuesday, April 11, 2017

Nanoparticles found in dozens of products can be inhaled, absorbed through the skin and ingested.

Georgia: Silently
helping our clothes resist stains, allowing spray-on sunscreen to more
easily protect our skin and enhancing paints, coatings and plastics.
Nanoparticles have even made their way into our food, including powdered
sugar on pastries, chewing gum and other products. Christa Wright,
assistant professor of environmental health in the Georgia State School
of Public Health, researches the potential health impacts of
nanoparticles, which can also be found in such everyday items as
cosmetics, the toner in photocopiers and artificial turf.
Nanoparticles can’t be seen with the eye or even with a microscope.
For a sense of perspective, consider the diameter of a strand of human
hair. That cross section of hair is the size of 100,000 nanometers. (A
nanometer is a billionth of a meter.)
Wright is among a pioneering group of scientists raising concerns
about these super tiny particles. While many nanomaterials start out as
substances that are considered safe at normal size, there has been very
little testing into how safe these particles are when they are made so
small they can travel easily from the lungs into other parts of the
body, even slipping into cells and potentially causing damage to DNA.

That means the titanium dioxide that is safe when you smear it on
your nose as a sunblock could be dangerous when it is broken down into
super tiny bits that can interact with the human body at a cellular
level.

The impact could be greater for populations that are already
vulnerable, such as people with inherited disorders, especially with
long-term exposure.
In one study, Wright found that certain metal-based engineered
nanoparticles, widely used in cosmetics and sunscreens such as zinc
oxide, could cause DNA damage in human cells.
People who work in the recycling and waste disposal industries may also face an increased risk due to exposure to nanomaterials.
In a recent study, Wright found that high-temperature incineration, a
common disposal method for thermoplastics that contain nanoparticles,
can result in a “nanofiller effect” where higher toxicity was observed
in the particles released during burning of nano-enabled plastics than
particles emitted from burned regular materials (plastics containing no
nanomaterials).
About 20,000 metric tons of “nanocomposite” materials (such as vinyl
siding) are sent to U.S. recycling facilities, landfills or disposed of
through incineration each year.
As with products sold directly to consumers, there is no requirement
that these materials be labeled and no guidelines for safe disposal of
nano-enabled products.
“We’re not trying to demonize any particular material,” Wright said.
“There are numerous benefits of nanomaterials across various industrial
and research sectors. However, by understanding the material properties
and how they behave in biological systems, we can minimize adverse human
health outcomes while capitalizing on their unique properties, thereby
increasing sustainability of the nanotechnology industry.”